On multivariable logistic regression among development cohort in the risk model, rectal cancer, poorly-undifferentiation, signet-ring cell carcinoma, CEA positive, N1/N2 stages, brain metastasis, liver metastasis and lung metastasis were significantly associated with higher risk of developing BM, which were used to develop the risk model of predicting BM. This evidence concerns the gene CEACAM5 and rectal cancer.